Global Warming

Global warming policies we set today will determine the next 10,000 years

The decisions made in the next couple of decades about reducing greenhouse gas emissions will determine the severity of global warming — including potentially catastrophic sea level rise — for the next 10,000 years, according to a provocative statement by prominent climate scientists.

The research, published Monday in the journal Nature Climate Change, examines the "deep time" implications of emissions of global warming pollutants such as carbon dioxide.

The study vividly demonstrates how the lag effects that are inherent in the climate system affect policy decisions that today's leaders must make through the middle of this century.

These lag effects — namely the ability of carbon dioxide to remain in the air for thousands of years, and the high sensitivity and long memory of global ice sheets to this temperature increase — will ensure that today's policy choices will play out on a stage longer than the history of human civilization.

"If carbon dioxide emissions continue unchecked, the carbon dioxide released during this century will commit Earth and its residents to an entirely new climate regime," the study states.

The study reviews evidence from ice cores, tree rings and other sources showing the past 20,000 years of the Earth's climate history, including how sea levels fell during the last ice age and rose as the climate entered a new, more stable and mild period known as the Holocene.

The study also notably details projections for the next 10,000 years based on different scenarios of rising greenhouse gas emissions from burning fossil fuels such as coal and oil.

For example, the study shows that future rates of sea level rise due to melting ice caps and warming, expanding seas, could be on the order of up to 4 meters, or 13.1 feet, per century, which would be unprecedented in more than 8,000 years.

Even if emissions were capped or reduced to some lower rate, we would still be committed to global mean sea level rise that is substantially larger than that experienced over much of recorded human civilization," the study states.